Pneumatic conveying means



Oct. 10, 1961 R. MARCHAND 3,003,821

PNEUMATIC CONVEYING MEANS Filed May 2'7, 1960 2 Sheets-Sheet 1 D J 22 23- l I l FIG.2

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PNEUMATIC CONVEYING MEANS Filed May 27, 1960 v 2 Sheets-Sheet 2 [/Vl/HV roe.- RH yM o/vp /VBI?CHHND United States Patent Ofi ice 3,003,821 Patented Oct. 10, 1961 3,003,821 PNEUMATIC CONVEYING MEANS Raymond Marchand, La Bedoule, Bouches-du-Rhone, France Filed May 27, 1960, Ser. No. 32,220 3 Claims. (Cl. 302-53) The purpose of the invention is to provide a pneumatic conveying device using a very low motive force, obtained by a variation in the apparent density of a powdered or granular material made fluid or inert alternately. This fiuidisation consists of the introduction, into a substance taking the form. of solid particles of small dimensions, of a gas which by its homogeneous propagation increases its volume while at the same time reducing its apparent density.

The invention aims at eliminating all mechanical elements and at utilising the advantages offered by the passage of the substance from the fluid to the inert state to set up and stop the movement by means of a fluid valve formed by the substance itself, by the action of the admission-, pressureor exhaust-valves.

It is characterised by the means used, considered both in conjunction with one another and separately, and more particularly by a pumping-device consisting of a pump-body, provided at the bottom with an air-pervious plate and an air-inlet or air-exhaust cock, and provided at the top with two valves, one for intake by suction and the other for expulsion, and also provided with a vertical column fitted at the bottom with an air-inlet plate. This apparatus can be combined with a sealingdevice based on the fluidisation and on the inert state of the substance, replacing the mechanical valve and comprising two concentric tubes, one for the admission and the other for the emergence of the substance being treated, these tubes being situated above one and the same porous plate, which is provided with an air-inlet and air-outlet cock.

On the attached drawings, illustrating a non-limitative example of the way in which the device to which the invention relates can be constructed:

FIG. 1 is a longitudinal section of the pumping-device with the articulated valves;

FIG. 2 is a fluid sealing-device in the same position;

FIG. 3 is a constructional variant of a sealing-device; with a number of elements;

FIG. 4 shows how the pump is assembled, with sealing-devices replacing the articulated valves;

FIG. 5 is a schematic diagram of a pneumatic transport-device with a number of stages, with fluid sealingdevices.

FIG. 6 is a schematic diagram of a stage-wise pneumatic transport-device of which the pump-body bases form fluid sealing-devices.

The apparatus consists of a storage-receptacle 1 (FIGS. 1, 2) fitted at its oblique base with an air-pervious plate which receives via the distributing-box 3 the compressed air coming from the conduit 4 via the valve 5; this set of equipment is completed by a relief-valve 6.

At the base of the storage-receptacle 1 there is the suction-valve 7, opening into the pump-body 8, which is equipped with the porous plate 9 with distributing-box 10, connected by the valve 11 to the distributing-conduit 4 with its relief-valve 6 and exhaust-branch 6'.

The upper part of the pump body 8 is fitted with an expulsion-valve 12 opening into the vertical expulsioncolumn 13.

This column comprises at its base, situated underneath the valve 12, a porous plate 15 and a distributing-box 16 connected by the cock 17 and the relief-valve 6 to the compressed-air supply-pipe 4.

The sealing-device in FIG. 2 consists of the receptacle 18, communicating with the pipe 19. This receptacle contains, concentrically, an immersion-chamber 20, extended in the form of the pipe 21.

The base of the receptacle is equipped with a porous plate 22 and an air-distributing box 23 connected by the conduit 24, which is equipped with a double-acting valve 25 controlling the air-inlet pipe 26, to the outlet-branch 27.

The receptacle 19 (FIG. 3) may comprise a number of immersed partitions 20, 20, 20"; FIG. 4 shows how the pumpingand sealing-devices are combined.

The pump 8 is intercalated between the two sealingdevices 28 and 29, having on one side the tank 1 and on the other side the expulsion-column 13. The valves 30, 31 and 32 are mounted on inletand outlet-branches.

FIG. 5 is a schematic diagram of a stage-wise pneumatic transport-device, again based on the same principle, with the hopper 1, the fluid sealing-device 33, the super-imposed pump-bodies 34, 35, 36 and 37, the sealing-devices 38, 39 and 40 for the pump-bodies, and the taps 41, 42, 43 and 44, which are sealed on the admis sion and the outlet and which feed the various porous plates, and conduits between the pump-bodies. The small pipes 47, 48 and 49 are air-exhaust pipes.

FIG. 6 is a schematic diagram of a further device, likewise with a number of stages, with the hopper 1, the pump-bodies 34, 35, 36 and 37, which at their base formfluid sealing-devices with expulsion-conduits and which are equipped at the top with porous air-exhaust plates. The taps 41, 42, 43 and 44, which are sealed on the admission and the outlet, feed the various porous plates.

The advantages ofiere'd by this device are numerous.

The pumping-action, as shown in FIG. 1, consists of inducing a fluid and then an inert state, alternately, in a pulverous substance. For this purpose, one opens the valve 7, which enables the substance in its inert state to be introduced into the body of the pump 8. This flow, as shown by the arrow A, is facilitated by the porous plate 2, situated in the tank 1. This admission-orifice is closed by the valve 7. The expulsion-orifice is opened by the valve 12 at the same time as the compressed-air cook 11. The fluidisation of the inert substance contained in the body 8 is effected by means of the plate 9, which distributes the currents of air. The swelling then takes place, and the increase in volume, as Well as the change in the apparent density, renders possible the transport-action, which takes place through the column 13, with an acceleration set up by the additional flushing-air emitted by the valve 17, passing through the plate 15, as shown by the arrows B and C.

The cycle is repeated, for the charging and the expulsion, by the action of the valve 5 and of the other valves, which close and open alternately, thus setting up the fluidised and the inert state in the substance in alternation.

"The device referred to as thesealing-system, which has the advantage of replacing the usual mechanical valves, operates in the conduits under pressure, this system consisting of inducing a fluid and an inert state alternately in the fiuidisable substance.

For this purpose, the two conduits l8 and 20 are open, at their bottom, to the porous plate 22, with air feed box 23 and pressureand outlet-cock 24. This provides a means of con-trolling the free circulation of the substance, as shown by arrows D and E, from one conduit to the other, or from 19 to 21 in the present example, or the natural sinking of the substance from the top downwards onto the porous plate, so that its movement can be stopped.

These devices, based on the same means, that is to say,

the system referred to as the pumpingand stoppingdevice, can be used separately, or combined together on one and the same apparatus.

In FIG. 4, for instance, the sealing-effect isv provided by the device described in connection with FIG, 2, by the substance itself, and no. wear takes place, since the valve is constantly renewed. The discharge of the substance in its inert state prevents any fiuidification and renders the sealing-device air-tight.

The valves 7 and 12 of FIG. 1 are replaced by the sealing-devices 28 and 2.9, situated on the inletand discharge-side of the pump-bodies. By the mere action of the valves 31), 31 and 32 the substance can be subjected to pressure or discharged, and it passes successively from the inert state, in which it operates as a sealing-device, to the fluid state, in which it is mobile, to be impelled into the vertical transport column 13.

The swelling which takes place from the top downwards prevents any sealing-effect. The low speed of movement eliminates the risk of breaking up of the substances transported. The fluid sealing-devices which replace the usual valves combine with the pump-bodies in an unlimited number, in order to set up a continuous pumping-action. In the same way, for high rates of delivery, two or more sealingdcvices can be adopted, or else one such device with a large cross-section in accordance with FIG. 3.

The pumping-operation, in accordance with the devices described is effected in vertical or other planes, so that in the examples given in connection with FIGS. and 6, for example, the substance from the hopper 1 passes through the sealing-device 33, which is open, and fills the pumpbody 34. The fluidised substance from. the pump-body 34 is expelled into the pump-body 35. The fluidised substance from the pump-body 35 is expelled into the pump-body 36, and the fluidised substance in the pumpbody 37 is expelled through the pipe 45, of which the conduit 46 forms a branch. At the end of the cycle, the taps 41 ad 42 are adjusted for the discharge-action, and the taps 43 and 4-4, are opened to admit the air. The substance is then fluidised in the pump-bodies 34. and 36 and expelled into 35 and 37.

These stage-wise devicesv enable over-pressure air to be utilised, at low pressure, in the place of compressed air.

These devices, which are entirely static and are very simple in their construction, enable the use of all mechanical parts in the circuit of the substance to. be dispensed with, which eliminates all risk of wear.

Thus, the pumping-effect hitherto obtained by varyingthe volume of the pump-body, thatis to say, with, the air of a mechanical movement performed by a piston or a diagram, is totally eliminated. The means described enable pumping-phenomena to be brought about by varying the apparent density of a pulverous substance, inwhich a fluid state and an inert state are set up alternately, one of these very same phases, namely the inert state, being utilised as a sealing-valve consisting of the substance itself, thus being constantly renewed without undergoing any wear.

The items of apparatus thus constructed occupy very little space by comparison with the present mechanical transport-devices. The inletand outlet-cocks, which are not in contact with the product being transported, are the sole devices in motion, which enables them to be adapted to all control-devices synchronised with the operation of the system as a whole.

The shapes, dimensions and arrangements adopted for the various elements in question may thus vary within the limits allowed by equivalent devices, as may likewise the materials used for their manufacture, without any departure from the general principle governing the invention described in the foregoing.

Icl-aim:

l. A statically operating pneumatic conveying device for powdered and granular materials comprising a storage receptacle having an opening at its lower part, a pump body disposed. below the storage receptacle and communicating at its upper end with the receptacle said pump body having an outlet at its upper end, air pcrvious means at the lower part of the storage receptacle for the controlled introduction of compressed air to fiuidise the. contents of the receptacle, other air-pervious means at the lower part of the pump body for controlled introduction of compressed air to fluidise the contents of the pump body, an expulsion column having an opening in its wall communieating with the outlet of the pump body, still further airpervious means at the lower part of the expulsion column for the controlled introduction of compressed air into the expulsion column to fluidise the contents thereof and expel the contents upwardly out of the column, first valve means positioned to act between the storage receptacle and the pump body for inlet to the pump body, and second valve means positioned to act between the pump body and the expulsion column for outlet from the pump body.

2. A statically operating pneumatic conveying device, as claimed in claim I, wherein each of the valve means is constituted, by a sealing device in which the conveyed material itself, in its nonafluidised' state, forms the sealing means, said sealing device comprising a receptacle having an inlet at its upper end and an air-impervious entry for compressed air at its lower end, and outlet conduit means depending in spaced relationship into said receptacle, said outlet conduit means being open at the upper end and terminating at the other end short of the lower end of the receptacle.

3. A statically operating pneumatic conveying device, as claimed in claim 2, wherein the outlet conduit means consists of a plurality of spaced conduits communicating with a common outlet header at their upper end and terminating short of the base of the receptacle at their lower end'.

References Cited in the file of this patent UNITED STATES PATENTS 2,667,280 Lane Jan. 26, 1954 2,715,548. Fish Aug. 16. 1955 2,756,981 Muller July 31, 1956 2,793,914 Gardeniers May 28, 1957 

